BTC daily surface: 1W ATM IV falls 2.71 volatility points
Across the six available headline tenors, ATM IV averaged -0.99 volatility points, RR25 +0.40 volatility points and BF25 -0.02 volatility points between the stored endpoints.
BTCSpot-index 24h Unavailable1W ATM IV 33.73%1W RR25 -4.15 vol pts1W BF25 +1.91 vol pts1W IV − 7D RV Unavailable
Market context · daily observation window
Market context
BTC spot-index return unavailable; 1W ATM IV fell 2.71 volatility points to 33.73% over the daily window. RR25 moved toward calls (+0.47 points); BF25 wing premium increased (+0.13 points); partial native coverage (3/4 measurements).
Previous report, watch levels and methodology
One-week surface context; the published headline retains its original evidence basis. Cutoffs 19 May, 23:59 UTC to 20 May, 23:59 UTC.
Measured change since prior report
Against the 2026-05-19 daily edition.
BTC 1W ATM IV: prior change -0.31 → current change -2.71 volatility points; same direction.
BTC 1W RR25: prior change +0.43 → current change +0.47 volatility points; same direction.
BTC 1W BF25: prior change -0.45 → current change +0.13 volatility points; direction reversed.
A structured watchlist was not recorded or could not be verified in the prior edition; this compares measured changes only.
Next daily cutoff: measurable checks
These checks are reconstructed from this edition’s stored endpoints; they were not recorded in the original report.
Hold the observed level: BTC 1W ATM IV ≤ 33.73 percent at . Current level 33.73; threshold is the current observed endpoint.
Full retrace: BTC 1W ATM IV ≥ 36.44 percent at . Current level 33.73; threshold is the previous observed endpoint.
Measurement basis and receipt
These are observed-level conditions for the next aligned cutoff, with no forecast or trade action. Spot uses exact index endpoints where available; ATM IV is quoted in percent and its change, RR25 and BF25 in volatility points. Derived from verified legacy artifact endpoints.
RR25 moved towards calls, averaging +0.40 volatility points to -5.06 volatility points across the six available headline tenors. Negative RR25 denotes a richer 25-delta put wing under the call-minus-put convention.
BF25 was broadly unchanged, averaging -0.02 volatility points to 2.19 volatility points across the six available headline tenors. BF25 measures the average 25-delta wing premium over ATM IV.
Contracts with fewer than 2 full days to expiry remain in the tables but are excluded from headline rankings. Settlement proximity, time decay, changing liquidity and fewer quotes can exaggerate their changes.
1.3d
ATM IV change
22MAY26, -5.41 vol pts0.3d
Smile rotation
21MAY26, +5.38 vol pts
10 · Volatility term structure
Today against the previous 24-hour snapshot.
Only fixed tenors bracketed by listed expiries at both snapshots are charted. The listed-expiry table preserves the observable exchange maturities underneath those interpolated points.
CurrentComparison snapshot
Expiry
Time left
Forward now (USD)
Forward change (USD)
ATM IV now
ATM IV change
RR25 change
BF25 change
21MAY26Expiry effect
0.3 days
77,466.2
+704.40 USD
27.46%
-4.47 vol pts
+2.18 vol pts
-0.58 vol pts
22MAY26Expiry effect
1.3 days
77,468.8
+702.35 USD
29.25%
-5.41 vol pts
+0.88 vol pts
+0.24 vol pts
23MAY26
2.3 days
77,479.72
+703.02 USD
31.21%
-4.05 vol pts
+0.78 vol pts
+0.06 vol pts
29MAY26
8.3 days
77,504.95
+694.66 USD
34.42%
-2.28 vol pts
+0.49 vol pts
+0.13 vol pts
5JUN26
15.3 days
77,529.02
+694.40 USD
35.33%
-1.23 vol pts
+1.22 vol pts
-0.24 vol pts
26JUN26
36.3 days
77,583.64
+706.80 USD
36.49%
-1.01 vol pts
+0.33 vol pts
-0.09 vol pts
31JUL26
71.3 days
77,757.26
+731.29 USD
37.83%
-0.58 vol pts
+0.43 vol pts
-0.05 vol pts
25SEP26
127.3 days
78,115.64
+734.69 USD
39.73%
-0.26 vol pts
+0.18 vol pts
-0.04 vol pts
25DEC26
218.3 days
78,816.27
+735.27 USD
42.71%
-0.23 vol pts
+0.14 vol pts
-0.04 vol pts
26MAR27
309.3 days
79,487.95
+743.07 USD
43.72%
-0.25 vol pts
+0.05 vol pts
+0.05 vol pts
11 · Smile movement
Reconstructed SVI smiles for every common expiry.
Each overlay uses the stored five-parameter SVI fit and the snapshot-specific time to expiry. Ultra-short expiries are displayed but do not determine the headline ranking.
21MAY26rotation towards calls · wing steepening22MAY26rotation towards calls · wing steepening23MAY26rotation towards calls · wing steepening29MAY26rotation towards calls · wing steepening5JUN26rotation towards calls · wing steepening26JUN26parallel shift lower31JUL26parallel shift lower25SEP26parallel shift lower25DEC26parallel shift lower26MAR27parallel shift lower
Surface movement heatmap
Each cell is the fitted IV change in volatility points. Rows are listed expiries; columns run from the put wing through ATM to the call wing.
IV lowerIV higher
21MAY26
22MAY26
23MAY26
29MAY26
5JUN26
26JUN26
31JUL26
25SEP26
25DEC26
26MAR27
-0.30kATM+0.30k
Evidence, source data and methodology
Report comparison baseline → current snapshot
2026-05-19 23:59:00 UTC → 2026-05-20 23:59:00 UTC
Changes use these stored market-snapshot baselines. The comparison baseline may differ from the snapshot used in the previous published edition.
Original report summary
Across the six available headline tenors, ATM IV averaged -0.99 volatility points, RR25 +0.40 volatility points and BF25 -0.02 volatility points between the stored endpoints.
At report cutoff · Levels and stored endpoint changes
What matters now
Vol: BTC 1W ATM IV 33.73% · Δ -2.71 vol pts
Skew: BTC 1W RR25 -4.15 vol pts · Δ +0.47 vol pts
Wings: BTC 1W BF25 1.91 vol pts · Δ +0.13 vol pts
Vol
BTC 1W ATM IV 33.73% · Δ -2.71 vol pts
Skew
BTC 1W RR25 -4.15 vol pts · Δ +0.47 vol pts
Wings
BTC 1W BF25 1.91 vol pts · Δ +0.13 vol pts
IV versus RV
BTC Unavailable
Unavailable readings: BTC IV versus RV. See the report’s data availability notes.
Δ compares the report’s stored surface endpoints. IV versus RV is a level comparison, not a daily change.
12 · Technical appendix
Model parameters and normalized Greeks.
These diagnostics preserve the fitted-surface audit trail without competing with the main market story.
Show SVI parameter changes and normalized Greeks
SVI diagnostics
Daily movement in a, b, rho, m and sigma.
Among ranking-eligible expiries, the largest absolute rho change occurred at 5JUN26; the largest sigma change occurred at 29MAY26.
Expiry
Δ a
Δ b
Δ rho
Δ m
Δ sigma
Smile classification
21MAY26
+0.01050
-0.02560
+0.03690
-0.00120
+0.01630
rotation towards calls, wing steepening
22MAY26
+0.05120
-0.04220
+0.07150
+0.06460
-0.33620
rotation towards calls, wing steepening
23MAY26
+0.04080
-0.03390
+0.06690
+0.05150
-0.24480
rotation towards calls, wing steepening
29MAY26
+0.04850
-0.03290
+0.10870
+0.03300
-0.25520
rotation towards calls, wing steepening
5JUN26
+0.03610
-0.02810
+0.19920
+0.09020
-0.15380
rotation towards calls, wing steepening
26JUN26
-0.00990
+0.00530
+0.00180
-0.00210
+0.03110
parallel shift lower
31JUL26
-0.02920
+0.00810
-0.08590
-0.06660
+0.10400
parallel shift lower
25SEP26
-0.06470
+0.02790
-0.03080
-0.04540
+0.13740
parallel shift lower
25DEC26
-0.05420
+0.02230
-0.00310
-0.02530
+0.09770
parallel shift lower
26MAR27
-0.07820
+0.03430
+0.02530
+0.00230
+0.11220
parallel shift lower
Current surface characteristics
Where normalized model Greek intensity is highest.
These are comparable Black-forward Greeks for a one-BTC ATM-forward call at each listed expiry—not portfolio exposure, open interest or a prediction of dealer positioning.
Thresholds are asset-specific policies recorded in this edition. Each window is assessed independently; returns spanning gaps are excluded. Partial estimates may miss volatility during gaps.
RV coverage and methodology
BTC · Unavailable · Surface cutoff 20 May 2026, 23:59:00 UTC · 7D coverage not recorded / not recorded required · largest 7D gap not recorded / not recorded maximum · maximum gap not recorded. RV suppressed — valid 7D coverage was not recorded. Full 7D coverage policy was not recorded.
Derivasys proprietary historical SVI surface database
Comparison window
Nearest successful surface snapshots approximately 24 hours apart
RR convention
25-delta call IV minus 25-delta put IV
BF convention
Average 25-delta wing IV minus ATM forward IV
Fixed tenors
Fixed-tenor measures are interpolated independently at 1W, 2W, 1M, 3M, 6M, 9M and 1Y; headline rankings prioritise 1W, 2W, 1M, 3M, 6M and 1Y.
Smile reconstruction
Listed-expiry smiles are reconstructed from stored SVI total-variance parameters on a fixed log-moneyness grid.
Ultra-short expiries
Expiries with fewer than 2 full days remaining stay in detailed tables but are excluded from headline rankings. Settlement proximity, time decay, changing liquidity and fewer quotes can exaggerate their changes.
Greek normalization
Black forward Greeks for a normalized one-BTC ATM-forward call, zero rate, fitted SVI IV
